1. Field
Dynamic, autonomous resource allocation and channel access can take place while using an overlaying cellular system uplink. For example, a local node can make measurements and calculate a probability of access on various channels, either acting individually or in cooperation with other local nodes or cluster nodes.
2. Description of the Related Art
Resource allocation in femto cells may have various prerequisite requirements. For example, in a synchronization method for femto-cell base stations in uncoordinated communication networks, the femto cell in question can obtain synchronization information from one other base station, and can adjust its own clock in response to the synchronization information. The timing synchronization information can be identified from a strongest synchronization signal from among nearby uncoordinated base stations. The timing synchronization can accommodate clock offsets and frequency offsets. Autonomously communicating devices could then determine suitable timing for their local operation in the cellular system uplink.
Deployment of femto cells with flexible spectrum use aiming at utilizing opportunistically overlaying cellular system uplink resources may encounter certain challenges. For example, when the local nodes or the cognitive femto cell of interest are deployed far enough away from the “victim” eNB to avoid causing any interference to that eNB, the femto cell may not be able to determine whether it is far enough away from the eNB, or how to select the most suitable carrier.